Liquid-level gauge



F. B. SMITHE LIQUID LEVEL GAUGE 2 Sheets-Sheet Filed July 28, 1925 A V'TOF VEYS 2 Sheets-Sheet F B SMITHE LIQUID LEVEL GAUGE Filed July 28, 1925 1111'). 'Il'llll Aug. 21, 1928.

Figure 3 is an inverted plan view of Figure 2;

Figure 4 is a vertical section of a modified form of tank instrument;

Figure 5 is an inverted plan view of Figure 4;

Figure 6 is an end elevation of the part of the mechanism shown in Figure 4;

Figure 7 is a vertical section of a further modified form of tank instrument; V

Figure 8 is an inverted plan View of'Fig- '5 by a tube 12 with the vacuum-tank13 situated above'the engine so as tofeed fuelthrough the tube 14 to the feed chamber of the carburetor 15. The vacuum tank is connected by a tube'or suction line 16 to the main or storage tank 17 carried on the rear of the vehicle, as is customary. inasmuch as the structural details .at the top of the-tank 17 form no part of the present invention, they areomitted from the drawing.

A" tank instrument, designated generally by theletter'ri is placed insidethe tank near the bottom, thereof. It is connected with the lower end 18 of the suction line'and provided with suitable passages, tobe described, for permitting the withdrawal of the liquid from the tank 17 l A liquid filled manometer 19 having a vented indicating leg 20 and a 'storagechamber 21 is connected by a gauge linetube 22 withthe tank instrument 'A. This gauge line provides a trapped air columnwhich extends from the storage chamber to the tank instrument A. Suitable passages, to bedescribed, are provided in-the tankinstrumentffor permitting the manometer to be actuated by the'hydro static pressure 'at the lower end of the gauge line," and for per- ,tion of the vacuum-fuel system, and restores mitting the withdrawal of the trapped air from the gauge line for the purpose of resetting thegauge; This resetting'operation is brought about by the intermittent opera- ,hefair'in the tube 22 to a predetermined datum pressure.

" The form 'oftank instrument shown in Figures 2 and 3 1s conveniently made up from-a metal block-25.' It is provldcd with a passage 26 extending" from the top to the bottom of the block and enlarged at the top as (shown at 26 for the reception of the 'lowerend 18 of the suction line. Itis also provided with a drilled passage 27" closed at thebottom and enlarged at the top as shown at 27to receive the lower end of the gauge line tube 22. These tubes may be an internal combustion;

soldered to the block. A downwardly slop? ing drilled passage 28 interconnectsthe passages 26 and 27 and forms a passage or conduitfor the interchange of air and liquid. This drilled passage 28 is plugged as shown at 29. In order to space the lower face 30 of the block above the bottom 31 of the tank 17,; the block may be provided with a spacing projection 32. The lower surfaceof the block is also preferably cut away as shown as 33 to provide lateral passages communicating with the passage 26. These and the passages 27' and-28 is sucked out due to the fact that the pressure tending to maintain the liquid in the tube is withdrawn and suction is appliedthereto instead. Air is admitted through the vented end of the manometer and'passes through the'tubing 22. This restores the trapped air column to a predetermined datum pressure, and ef fects aresetting of the gauge; Iii-the form of'tankinstrument shown in Figures 4, 5 and6, a block 35 is provided with a side opening recess 36 in its lower face and with vertical passages 37 and 38 extending from; the top of the blockdown to saidrecess. -The suction line .18 is fastened as by soldering into the left hand pas sage while the gauge tube 22' is passed IOU through theright hand passage. The lower end 39 of the tube 2-2 is preferably constructed, in the manner indicated, I and beveled as shown at 4-0 to'facilitate the sucking out" ofv the liquid in this tube, when the vacuunrtank operates. This form of tank instrument is preferably 7. placed in contact width the bottom-0f the tank, as indicated.

The operation issimilar to that already described.

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Figures? to 10 inclusive show a modified form of tank lnstrumentp Here] a metal "the suction line 18 which leads into a 'block41 is provided with a passage 42 for block and with a passage 45, enlarged at t ,45: for thereception of the'gauge tube 22".

The side face 44, of the blockis provided with a channel 46below the cavity'43, and

oblique'passages' t'l run from this channel to thepassage 45. 'This form of block is provided 'witha u shaped' cover member 48 which maybesuitabl-y fastened in place. It will be noted that this member provides awall of the cavity 43 and channel 46 so that the fuel passage extends to the lower face of the block. The lower portion 49 of the cover member/has an irregular configuration'such as indicated to provide-lateral pasaqewayiar the, fuel. small vent '50 may l) the latter is in operative position in the tank, and a second downwardly extending passage which communicates'with the gauge pipe and with the first ment oned passage,

- the passages being so inter-related that the application of suction to the suction pipe will withdraw liquid from the gauge pipe. 2. In a tank instrument for liquid level gauges, a suction pipe, awgauge pipe, a block connected to said pipes, said "block having a passage therein which communicates withthe suction pipe and is adapted to open into the tank at the lower side of the block when the latter is in operative position in the tank, and a second downwardly extending passage which communicates with the gauge pipe and with the first mentioned passage, the passages being so inter-related that the application of suction to the suction pipe will withdraw liquid from the gauge pipe, said block also having a lateral channel in its lower side in communication with the first passage. p a

8. In a tank instrument-for liquid level gauges, in combination, a suction pipe, a gauge pressure pipe, and a block into the upper side of which the two pipesextend, said block having apassage communicating with the suction pipe and extending to the lower side of the block, and a passage comvmunicating with the gaugev pressure pipe andleading into the first passage.

4:. In a tank instrument for liquidklevel gauges, a block having an upwardly and downwardly opening vertical'passage therein, a suction pipe extending into the passage, a second upwardly opening vertical passage in the block, a gauge pressure pipe extending into the second mentioned passage, there being lateral passage in the lower face of the block in communication with the first passage,and an interconnecting passage leading from the first to the second passage, said passages being so interrelated that the application of suction to the suctionpipe will withdraw liquid from the gauge pressure pipe when the instru ment is. submerged in a tank.

5. In a tank instrument for liquid level gauges, a block having a pair of upwardly extending passages for connecting pipes, one only of the passages being open at the bottom, and a passage connecting the two first mentioned passages and so disposed that sucking liquid upwardly through the downfor connecting pipesfone only of the -pasin sages being-open at kthe lbottom, there being1 a passage connecting theflt'wo first mentions passages and so disposed that sucking; liquid upwardly tl'irough the "downwardly opening passage will draw it downwardly through the other, and a lateral passage in the lower face of the block incommunication with the downwardly opening passage.

7. The combination with a liquid storage tank, a vacuum feed 'fuel system for withdrawing liquid from said tank, and a liquid level gauging means for gauging the liquid in said tank, said system and gauging means each including a tube extending from the top of the tank down toward the bottom of the tank, of a metal'blockattached to both of the tubes, and having passages communicating with the feed system tube and the gauge tube, respectively, and interconnected with one another in such manner that the application of suction to the fuelsystem tube to 1 draw liquid from the tank will draw air through the gauge tube, the first mentioned passage being open; at a point below that at which it communicates with the latter passage.

tank, a vacuum feed fuel system for with 8. The combinationwith a liquid storage drawing liquid-from said tank, and a liquid level gauging means for gauging the liquid insaid tank, said system and-gauging means, each including a tube extending from the top of the tank down toward the bottom of thetank, of a metal block attached to both of the tubes, and having passages communieating with the feed system tube and the gauge tube, respectively, and interconnected with one another-in such manner that the application of suction to the fuel system tube to draw liquid from the tank will draw air through the gauge tube, said block also having lateral P g in the lower faceit thereof leading to the first mentioned pas Y sage,

9. The combination with a liquidlstorage tank, a vacuum feed fuel system ,for withdrawing liquid from said tank, and a liquid level gauging means for gauging the liquid in said tank, said system and gauging means each including a tube extending-from the top of the tank down toward the bot tom of the tank, of a metal block attached to bothof the tubes, and having a passageway extending from the fuel system tube to the lower side of the block, and a second passageway including a downwardly sloping passage interconnecting the gauge tube and the first passageway. l

10. The combination with a liquid storage tank, a vacuum feed ,fuel system for l '5 from the top. of the tank down towardthe bottom ofthe tank, of a netal bloek attached-t0 both of the. tubes, and having a passageway extending from the fuel system tube tethe lower sicleo f the' blo ck, gt s'econd H passageway including a downwardlysloping passage interconnecting the gauge tube and thevfirst passageway, and a lateral pas: sage in thelower face of the block andleadingto the first passageway. i

In testimony whereof I signature to this; specification.

i "FRANK.- Bi SMITI-IE; 

